1. Field of the Invention
The present invention relates to electrical machines in general, and in particular, to the type of electrical machines that allow circuit cards to be plugged and unplugged from one side, usually the front. These electrical machines are sometimes called xe2x80x9cFront Accessxe2x80x9d machines.
2. Prior Art
Because of the rapid explosion in the use of computers and related electrical equipment (e.g., routers, concentrators and other networking devices), there has been a desire to manufacture more user friendly equipment. One of the areas targeted for improvement is the mechanical structure of the devices. In particular, the insertion of circuit cards or circuit boards into machine housings has been targeted for improvement.
The conventional PC or related electronic equipment includes a housing or cabinet in which a motherboard and/or one or more circuit boards are mounted. Electrical communication between the components is effectuated by electrical connectors mounted on the motherboard and the circuit cards. The arrangement between the card and the motherboard can be broadly classified into two groups.
In one group of machines, the card and its connector are inserted in a direction perpendicular to the connector on the motherboard. Examples of prior art devices in this group are set forth in U.S. Pat. No. 3,017,232 (Re 25595); U.S. Pat. Nos. 3,711,814; 4,789,352; 4,941,840; 5,238,423 and 5,363,281.
One of the problems with devices in this group is that most of the cabinetry (housing) has to be removed before the card can be inserted or removed.
Another problem is that a trained technician is usually required in order to change cards. As a consequence, the cost to maintain these machines are unnecessarily high.
In the other group of machines, the card and attached connector are inserted in a parallel direction relative to the motherboard connector. The card is then moved in a perpendicular direction in order to bring the motherboard connector and card connector into mating relationship. Even though this design is a step in the right direction, it is prone to bring damage to the contacts because insertion of the (male or female) connectors are skewed rather than direct. To minimize the likelihood of damage, a more accurate and precise mechanism is required to insert/remove circuit card or board into/from the housing.
Examples of prior art devices in this group are set forth in U.S. Pat. Nos. 3,869,185; 4,445,740; 5,302,136; 5,317,481; 5,325,269 and 5,366,385.
A general observation with the prior art is that the casing or chassis in which the cards are inserted are unnecessarily large in order to accommodate the tools and operations required to insert or remove a card. In addition, the installation procedures are usually complex and not user friendly.
It is, therefore, an object of the present invention to provide a user friendly and simple installation assembly for inserting or removing cards from a PC or similar machine.
It is another object to provide a device for front card insertion of standard PCI form factor cards.
In accordance with the present invention, an electrical machine comprising a housing with guides positioned within the housing means and at least one sub-assembly for mounting in said housing is disclosed.
The sub-assembly includes a frame for supporting a printed circuit board and an actuator bar with a push arm for positioning the frame. The frame includes a carrier plate and a side portion, hereinafter called locking CAM slide, having a front end, a back end, an outside edge and an inside edge extending along its lengthwise dimensions. A guide member, for providing easy insertion of the sub-assembly in the housing, is provided at the front end of the locking CAM slide. A semi-circular notch, allowing easy access to the push arm, is fabricated on the back end of the locking CAM slide. At least one slot, having one (angled) section oriented at an angle to the inside edge and at least one (horizontal) section orientated substantially parallel to the inside edge, is fabricated on the side portion. A locking structure is also provided in the slot. The slot includes at least one access opening.
The actuator bar includes a substantially U-shaped structure with a substantially U-shaped channel and a pin extending from one of the sides into the channel. In forming the sub-assembly, the locking CAM slide is slideably mounted in the channel and the pin is aligned in the slot. The relationship between the locking CAM slide and the actuator is such that when the pin is positioned at the locking structure, there is no relative motion between the actuator bar and the side portion. Stated another way, the actuator bar is locked. When the pin is displaced from the locking structure, the actuator bar moves relative to the locking CAM slide.
Fastening mechanisms for connecting the locking CAM slide to the carrier plate are provided on the carrier plate and the CAM slide.
In another feature of the present invention, the slot includes a second horizontal section contiguous with the opening and the angled section. The length of the second horizontal section is such that the handle of the actuator bar is pulled into the cabinet until the end sits flush with the front opening of the cabinet.
In another feature, a second pin is fabricated in the actuator bar and rides in a second slot fabricated in the locking CAM slide.
The foregoing features and advantages of the invention will be more fully described in the accompanying drawings.